irq.c

linux 内核源代码

			"%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn);
		return;
	}

	for( h = pirq_routers; h->vendor; h++) {
		/* First look for a router match */
		if (rt->rtr_vendor == h->vendor && h->probe(r, pirq_router_dev, rt->rtr_device))
			break;
		/* Fall back to a device match */
		if (pirq_router_dev->vendor == h->vendor && h->probe(r, pirq_router_dev, pirq_router_dev->device))
			break;
	}
	printk(KERN_INFO "PCI: Using IRQ router %s [%04x/%04x] at %s\n",
		pirq_router.name,
		pirq_router_dev->vendor,
		pirq_router_dev->device,
		pci_name(pirq_router_dev));

	/* The device remains referenced for the kernel lifetime */
}

static struct irq_info *pirq_get_info(struct pci_dev *dev)
{
	struct irq_routing_table *rt = pirq_table;
	int entries = (rt->size - sizeof(struct irq_routing_table)) / sizeof(struct irq_info);
	struct irq_info *info;

	for (info = rt->slots; entries--; info++)
		if (info->bus == dev->bus->number && PCI_SLOT(info->devfn) == PCI_SLOT(dev->devfn))
			return info;
	return NULL;
}

static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
{
	u8 pin;
	struct irq_info *info;
	int i, pirq, newirq;
	int irq = 0;
	u32 mask;
	struct irq_router *r = &pirq_router;
	struct pci_dev *dev2 = NULL;
	char *msg = NULL;

	/* Find IRQ pin */
	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
	if (!pin) {
		DBG(KERN_DEBUG " -> no interrupt pin\n");
		return 0;
	}
	pin = pin - 1;

	/* Find IRQ routing entry */

	if (!pirq_table)
		return 0;
	
	DBG(KERN_DEBUG "IRQ for %s[%c]", pci_name(dev), 'A' + pin);
	info = pirq_get_info(dev);
	if (!info) {
		DBG(" -> not found in routing table\n" KERN_DEBUG);
		return 0;
	}
	pirq = info->irq[pin].link;
	mask = info->irq[pin].bitmap;
	if (!pirq) {
		DBG(" -> not routed\n" KERN_DEBUG);
		return 0;
	}
	DBG(" -> PIRQ %02x, mask %04x, excl %04x", pirq, mask, pirq_table->exclusive_irqs);
	mask &= pcibios_irq_mask;

	/* Work around broken HP Pavilion Notebooks which assign USB to
	   IRQ 9 even though it is actually wired to IRQ 11 */

	if (broken_hp_bios_irq9 && pirq == 0x59 && dev->irq == 9) {
		dev->irq = 11;
		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, 11);
		r->set(pirq_router_dev, dev, pirq, 11);
	}

	/* same for Acer Travelmate 360, but with CB and irq 11 -> 10 */
	if (acer_tm360_irqrouting && dev->irq == 11 && dev->vendor == PCI_VENDOR_ID_O2) {
		pirq = 0x68;
		mask = 0x400;
		dev->irq = r->get(pirq_router_dev, dev, pirq);
		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
	}

	/*
	 * Find the best IRQ to assign: use the one
	 * reported by the device if possible.
	 */
	newirq = dev->irq;
	if (newirq && !((1 << newirq) & mask)) {
		if ( pci_probe & PCI_USE_PIRQ_MASK) newirq = 0;
		else printk("\n" KERN_WARNING
			"PCI: IRQ %i for device %s doesn't match PIRQ mask "
			"- try pci=usepirqmask\n" KERN_DEBUG, newirq,
			pci_name(dev));
	}
	if (!newirq && assign) {
		for (i = 0; i < 16; i++) {
			if (!(mask & (1 << i)))
				continue;
			if (pirq_penalty[i] < pirq_penalty[newirq] && can_request_irq(i, IRQF_SHARED))
				newirq = i;
		}
	}
	DBG(" -> newirq=%d", newirq);

	/* Check if it is hardcoded */
	if ((pirq & 0xf0) == 0xf0) {
		irq = pirq & 0xf;
		DBG(" -> hardcoded IRQ %d\n", irq);
		msg = "Hardcoded";
	} else if ( r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \
	((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask)) ) {
		DBG(" -> got IRQ %d\n", irq);
		msg = "Found";
		eisa_set_level_irq(irq);
	} else if (newirq && r->set && (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
		DBG(" -> assigning IRQ %d", newirq);
		if (r->set(pirq_router_dev, dev, pirq, newirq)) {
			eisa_set_level_irq(newirq);
			DBG(" ... OK\n");
			msg = "Assigned";
			irq = newirq;
		}
	}

	if (!irq) {
		DBG(" ... failed\n");
		if (newirq && mask == (1 << newirq)) {
			msg = "Guessed";
			irq = newirq;
		} else
			return 0;
	}
	printk(KERN_INFO "PCI: %s IRQ %d for device %s\n", msg, irq, pci_name(dev));

	/* Update IRQ for all devices with the same pirq value */
	while ((dev2 = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev2)) != NULL) {
		pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin);
		if (!pin)
			continue;
		pin--;
		info = pirq_get_info(dev2);
		if (!info)
			continue;
		if (info->irq[pin].link == pirq) {
			/* We refuse to override the dev->irq information. Give a warning! */
		    	if ( dev2->irq && dev2->irq != irq && \
			(!(pci_probe & PCI_USE_PIRQ_MASK) || \
			((1 << dev2->irq) & mask)) ) {
#ifndef CONFIG_PCI_MSI
		    		printk(KERN_INFO "IRQ routing conflict for %s, have irq %d, want irq %d\n",
				       pci_name(dev2), dev2->irq, irq);
#endif
		    		continue;
		    	}
			dev2->irq = irq;
			pirq_penalty[irq]++;
			if (dev != dev2)
				printk(KERN_INFO "PCI: Sharing IRQ %d with %s\n", irq, pci_name(dev2));
		}
	}
	return 1;
}

static void __init pcibios_fixup_irqs(void)
{
	struct pci_dev *dev = NULL;
	u8 pin;

	DBG(KERN_DEBUG "PCI: IRQ fixup\n");
	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
		/*
		 * If the BIOS has set an out of range IRQ number, just ignore it.
		 * Also keep track of which IRQ's are already in use.
		 */
		if (dev->irq >= 16) {
			DBG(KERN_DEBUG "%s: ignoring bogus IRQ %d\n", pci_name(dev), dev->irq);
			dev->irq = 0;
		}
		/* If the IRQ is already assigned to a PCI device, ignore its ISA use penalty */
		if (pirq_penalty[dev->irq] >= 100 && pirq_penalty[dev->irq] < 100000)
			pirq_penalty[dev->irq] = 0;
		pirq_penalty[dev->irq]++;
	}

	dev = NULL;
	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
		pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
#ifdef CONFIG_X86_IO_APIC
		/*
		 * Recalculate IRQ numbers if we use the I/O APIC.
		 */
		if (io_apic_assign_pci_irqs)
		{
			int irq;

			if (pin) {
				pin--;		/* interrupt pins are numbered starting from 1 */
				irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
	/*
	 * Busses behind bridges are typically not listed in the MP-table.
	 * In this case we have to look up the IRQ based on the parent bus,
	 * parent slot, and pin number. The SMP code detects such bridged
	 * busses itself so we should get into this branch reliably.
	 */
				if (irq < 0 && dev->bus->parent) { /* go back to the bridge */
					struct pci_dev * bridge = dev->bus->self;

					pin = (pin + PCI_SLOT(dev->devfn)) % 4;
					irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number, 
							PCI_SLOT(bridge->devfn), pin);
					if (irq >= 0)
						printk(KERN_WARNING "PCI: using PPB %s[%c] to get irq %d\n",
							pci_name(bridge), 'A' + pin, irq);
				}
				if (irq >= 0) {
					printk(KERN_INFO "PCI->APIC IRQ transform: %s[%c] -> IRQ %d\n",
						pci_name(dev), 'A' + pin, irq);
					dev->irq = irq;
				}
			}
		}
#endif
		/*
		 * Still no IRQ? Try to lookup one...
		 */
		if (pin && !dev->irq)
			pcibios_lookup_irq(dev, 0);
	}
}

/*
 * Work around broken HP Pavilion Notebooks which assign USB to
 * IRQ 9 even though it is actually wired to IRQ 11
 */
static int __init fix_broken_hp_bios_irq9(const struct dmi_system_id *d)
{
	if (!broken_hp_bios_irq9) {
		broken_hp_bios_irq9 = 1;
		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n", d->ident);
	}
	return 0;
}

/*
 * Work around broken Acer TravelMate 360 Notebooks which assign
 * Cardbus to IRQ 11 even though it is actually wired to IRQ 10
 */
static int __init fix_acer_tm360_irqrouting(const struct dmi_system_id *d)
{
	if (!acer_tm360_irqrouting) {
		acer_tm360_irqrouting = 1;
		printk(KERN_INFO "%s detected - fixing broken IRQ routing\n", d->ident);
	}
	return 0;
}

static struct dmi_system_id __initdata pciirq_dmi_table[] = {
	{
		.callback = fix_broken_hp_bios_irq9,
		.ident = "HP Pavilion N5400 Series Laptop",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
			DMI_MATCH(DMI_BIOS_VERSION, "GE.M1.03"),
			DMI_MATCH(DMI_PRODUCT_VERSION, "HP Pavilion Notebook Model GE"),
			DMI_MATCH(DMI_BOARD_VERSION, "OmniBook N32N-736"),
		},
	},
	{
		.callback = fix_acer_tm360_irqrouting,
		.ident = "Acer TravelMate 36x Laptop",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
		},
	},
	{ }
};

static int __init pcibios_irq_init(void)
{
	DBG(KERN_DEBUG "PCI: IRQ init\n");

	if (pcibios_enable_irq || raw_pci_ops == NULL)
		return 0;

	dmi_check_system(pciirq_dmi_table);

	pirq_table = pirq_find_routing_table();

#ifdef CONFIG_PCI_BIOS
	if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN))
		pirq_table = pcibios_get_irq_routing_table();
#endif
	if (pirq_table) {
		pirq_peer_trick();
		pirq_find_router(&pirq_router);
		if (pirq_table->exclusive_irqs) {
			int i;
			for (i=0; i<16; i++)
				if (!(pirq_table->exclusive_irqs & (1 << i)))
					pirq_penalty[i] += 100;
		}
		/* If we're using the I/O APIC, avoid using the PCI IRQ routing table */
		if (io_apic_assign_pci_irqs)
			pirq_table = NULL;
	}

	pcibios_enable_irq = pirq_enable_irq;

	pcibios_fixup_irqs();
	return 0;
}

subsys_initcall(pcibios_irq_init);


static void pirq_penalize_isa_irq(int irq, int active)
{
	/*
	 *  If any ISAPnP device reports an IRQ in its list of possible
	 *  IRQ's, we try to avoid assigning it to PCI devices.
	 */
	if (irq < 16) {
		if (active)
			pirq_penalty[irq] += 1000;
		else
			pirq_penalty[irq] += 100;
	}
}

void pcibios_penalize_isa_irq(int irq, int active)
{
#ifdef CONFIG_ACPI
	if (!acpi_noirq)
		acpi_penalize_isa_irq(irq, active);
	else
#endif
		pirq_penalize_isa_irq(irq, active);
}

static int pirq_enable_irq(struct pci_dev *dev)
{
	u8 pin;
	struct pci_dev *temp_dev;

	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
	if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
		char *msg = "";

		pin--;		/* interrupt pins are numbered starting from 1 */

		if (io_apic_assign_pci_irqs) {
			int irq;

			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
			/*
			 * Busses behind bridges are typically not listed in the MP-table.
			 * In this case we have to look up the IRQ based on the parent bus,
			 * parent slot, and pin number. The SMP code detects such bridged
			 * busses itself so we should get into this branch reliably.
			 */
			temp_dev = dev;
			while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
				struct pci_dev * bridge = dev->bus->self;

				pin = (pin + PCI_SLOT(dev->devfn)) % 4;
				irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number, 
						PCI_SLOT(bridge->devfn), pin);
				if (irq >= 0)
					printk(KERN_WARNING "PCI: using PPB %s[%c] to get irq %d\n",
						pci_name(bridge), 'A' + pin, irq);
				dev = bridge;
			}
			dev = temp_dev;
			if (irq >= 0) {
				printk(KERN_INFO "PCI->APIC IRQ transform: %s[%c] -> IRQ %d\n",
					pci_name(dev), 'A' + pin, irq);
				dev->irq = irq;
				return 0;
			} else
				msg = " Probably buggy MP table.";
		} else if (pci_probe & PCI_BIOS_IRQ_SCAN)
			msg = "";
		else
			msg = " Please try using pci=biosirq.";

		/* With IDE legacy devices the IRQ lookup failure is not a problem.. */
		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5))
			return 0;

		printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
		       'A' + pin, pci_name(dev), msg);
	}
	return 0;
}